attachment_icon filter-hook . WP 1.0

Usage

add_filter( 'attachment_icon', 'filter_function_name_6536', 10, 2 );
function filter_function_name_6536( $icon, $ID ){
	// filter...

	return $icon;
}

$icon

-

$ID

-

Where the hook is called

return apply_filters( 'attachment_icon', $icon, $post->ID );

Where in WP core the hook is used WordPress